DE102015100215A1 - Side channel blower for an internal combustion engine - Google Patents

Abstract

There are side channel blower for internal combustion engines with a flow housing (10, 12), an impeller (16) which is rotatably disposed in the flow housing (10, 12), impeller blades (32) formed at the radially outer portion of the impeller (16) and are formed radially outwardly open, a radial gap (50) between the impeller (16) and the impeller (16) radially surrounding housing wall (42), an inlet (18) and an outlet (30) and two the inlet (18 ) conveying channels (20, 22) for gas, communicating with the outlet (30), which are formed axially opposite the impeller blades (32) in the flow housing (10, 12) and are fluidly interconnected via spaces between the impeller blades (32), a drive unit (14), via which the impeller (16) can be driven, an interruption region (40) between the outlet (30) and the inlet (18), in which the delivery channels (20, 22) are interrupted in the circumferential direction ind, known. In order to increase the efficiency of such side channel blower, it is proposed that the impeller blades (32) are V-shaped in cross-section, that the impeller blades (32) extend in the direction of rotation inclined to the axis of rotation in the direction of its opposite conveying channel (20, 22).

Description

The invention relates to a side channel blower for an internal combustion engine with a flow housing, an impeller which is rotatably disposed in the flow housing, impeller blades which are formed on the radially outer portion of the impeller and are formed radially outwardly open, a radial gap between the impeller and a Impeller radially surrounding housing wall, an inlet and an outlet and two the inlet to the outlet connecting gas delivery channels, which are axially opposite to the impeller blades in the flow housing and are fluidly interconnected via gaps between the impeller blades, a drive unit via which the Impeller is drivable and an interruption area between the outlet and the inlet, in which the conveying channels are interrupted in the circumferential direction.

Side channel blowers or pumps are well known and described in a variety of applications. In the motor vehicle, they serve, for example, for conveying fuel or for blowing secondary air into the exhaust system or for conveying hydrogen for PEM fuel cell systems. The drive is usually via an electric motor, on the output shaft, the impeller is arranged. There are side duct blowers are known in which only one conveyor channel is formed on one axial side of the impeller in a housing part, as well as side channel blower in which a delivery channel is formed on both axial sides of the impeller, then both conveyor channels are fluidly interconnected. In such a side channel blower one of the delivery channels is usually formed in a serving as a lid housing part, while the other delivery channel is formed in the housing part to which usually the drive unit is attached to the shaft of which the impeller is arranged at least rotationally fixed. The impeller is formed at its periphery substantially such that it forms with the surrounding him the impeller conveyor channel or the surrounding conveyor channels one or two circumferential vortex channels.

In side channel blowers with two axially opposed swirl ducts, the impeller vanes are divided axially over a radial section into two sections associated with the respective opposite conveying channel. Between the impeller blades pockets are formed, in which receives the pumped fluid upon rotation of the impeller through the impeller blades acceleration in the circumferential direction and in the radial direction, so that in the delivery channel, a circumferential vortex flow. An overflow from one delivery channel to the other comes about in the case of radially open wheels mostly via the gap between the radial end of the impeller and the radially opposite side wall.

In order to obtain the best possible promotion or pressure increase, different measures have been taken in the promotion of gases and liquids due to the different behavior in the promotion of compressible or non or low-compressible media.

Furthermore, in the promotion in side channel blower noise is to be noted, because it acoustically disturbing pressure surges immediately after sweeping each impeller blade at the beginning of the interruption area, as in the pockets between the impeller blades still compressed gas is present, which is not completely on the outlet was ejected and is accelerated when reaching the interruption area suddenly against the walls. This leads to significantly increased noise emissions.

To increase the delivery pressure is in the US Pat. No. 6,422,808 B1 proposed a side channel blower for a compressible fluid having an impeller which is enclosed by a flow housing with two side channels, which has a fluid inlet and a fluid outlet. On the circumference of the impeller blades are arranged, which extend in the axial and radial directions and having a counter to the rotational direction of the rotor inclined radially inner portion and an inclined in the direction of rotation of the rotor radial outer portion and during rotation of the rotor fluid from the inlet to Promote outlet. At the radially inner portion, the blades each have a groove.

Furthermore, from the US 5,299,908 B1 a side channel blower known, the impeller blades extend straight in the radial direction, but are inclined relative to the rotational axis in the direction of rotation to the opposite side channel. However, between these two axial blade parts, a radial partition wall is arranged, which prevents an overflow from one channel to another by the impeller. Also, only a radially outer part of the blades is formed opposite to the delivery channel.

Such inclined and separate blades are also known from an impeller of a side channel pump for an incompressible medium. In addition, this impeller has a radially limiting side wall.

However, all these blowers and pumps are not optimal in terms of their delivery rate or with respect to the possible pressure increase.

It is therefore an object to provide a side channel blower with which the delivery rate or the delivery pressure can be further increased without increasing the diameter or speed further by the flow conditions in the delivery channels and the impeller are optimized or at the same flow rates to ensure lower power consumption of the drive. In addition, this fan should be suitable for various applications and delivery rates and have the lowest possible noise.

This object is achieved by the characterizing part of the main claim.

Contrary to expectations, such optimization in the delivery of compressible media is achieved by a side channel blower in which the impeller vanes are V-shaped in cross-section such that the impeller blades extend in the direction of rotation inclined to the axis of rotation in the direction of its opposite conveyor channel. At the same time, the impeller is formed in the radially outer region both axially and radially open, so that the gas is collected and accelerated in the axial center of the blade, which has proven to be an advantage for the formation of the spiral flow, with a steady exchange between the two delivery channels is possible. Such a side channel blower has a higher efficiency and covers a wide range of operating points.

An optimal inclination of the blades to the axis of rotation is 5 ° to 20 ° in the direction of rotation of the impeller. At such an angle, a particularly good efficiency is achieved, since an optimal pressure inside the blades is achieved.

Preferably, the impeller blades are inclined in their radially outer end region in the direction of rotation of the impeller to the radially inwardly adjacent intermediate region of the impeller blades. As a result, an additional acceleration is generated during the radial movement of the medium to the outside, through which the efficiency is further improved.

In a further development of the invention, the radial end portion of the impeller blades is inclined to the radial direction 5 ° to 20 ° inclined in the direction of rotation and the adjoining intermediate portion of the impeller blades by 5 ° to 20 ° counter to the direction of rotation inclined to the radial direction. These angles of attack result in optimized efficiencies of the blower.

In a particularly advantageous embodiment of the invention, the radial gap between the end region of the impeller blades and the housing wall radially surrounding the impeller in the region of the conveying channels is 0.03 to 0.1 times the impeller diameter. This means that the gap has been significantly reduced in comparison to known designs, which leads contrary to expectations in connection with the correspondingly shaped impeller blades to improved results.

In this embodiment of the impeller, it has additionally proved to be positive when the outlet extends in the flow housing tangentially from the conveyor channels and has a circular cross-section which substantially corresponds to the cross section of the conveyor channels. This training reduces the resulting noise emissions and leads to a good discharge of the flow and thus also to high flow rates.

In a further embodiment, at the level of the connection between the two legs of the V-shaped impeller vanes, a dividing wall is formed which extends radially across the intermediate region of the impeller vanes which adjoins the end region. As a result, pressure losses are prevented by an axial confluence of the two gas streams from the two delivery channels at the radially inner edge of the impeller blades or the delivery channels.

Thus, a side channel blower is provided in which compared to known side channel blowers for compressible media, the delivery rate or the potential pressure increase can be improved or the power consumption is reduced at the same flow rates, so that the efficiency is improved. At the same time, a very wide power range is covered by a blower size and noise emissions are reduced.

An embodiment of a side channel blower according to the invention is shown in the figures and will be described below.

1 shows a side view of a side channel blower according to the invention in a sectional view.

2 shows a perspective view of a section of the impeller of the side channel blower of 1 ,

3 shows a perspective view of a bearing housing of the side channel blower according to the invention 1 ,

This in 1 shown side channel blower has a two-part flow housing, which consists of a bearing housing 10 and a housing cover fastened thereto, for example by screws 12 consists. In the bearing housing 10 is a via a drive unit 14 rotatable impeller 16 stored. The conveyed compressible medium passes through an axial inlet 18 that is in the case cover 12 is formed, in the interior of the side channel blower.

From the inlet 18 from the medium then flows into two substantially annular extending delivery channels 20 . 22 of which the first conveying channel 20 in the bearing housing 10 is formed, in its central opening 24 also a storage 26 a drive shaft 28 the drive unit 14 is arranged on the impeller 16 is attached and the second conveyor channel 22 in the housing cover 12 is trained. The exit of the air takes place via a tangential outlet 30 in the bearing housing 10 is trained.

The impeller 16 is between the housing cover 12 and the bearing housing 10 arranged and has impeller blades at its periphery 32 on, extending from a disc-shaped middle section 34 extend, which on the one axis of rotation X of the impeller 16 forming drive shaft 28 is attached, and to which the two delivery channels 20 . 22 are formed axially opposite one another.

To reliably a short-circuit flow against the direction of rotation of the impeller 16 from the inlet 18 to the outlet 30 to stop are between the inlet 18 and the outlet 30 interruption regions 36 . 38 on the housing cover 12 and on the bearing housing 10 arranged, which the delivery channels 20 . 22 interrupt, leaving in the interruption areas 36 . 38 axially opposite the impeller blades 32 of the impeller 16 the smallest possible gap is available. In addition, there is also an interruption area acting in the radial direction 40 at one of the delivery channels 20 . 22 radially limiting housing wall 42 of the flow housing 10 . 12 educated.

The in the bearing housing 10 and in the housing cover 12 arranged conveyor channels 20 . 22 have a substantially constant width and extend with the exception of the interruption areas 36 . 38 . 40 over the circumference of the housing cover 12 and the bearing housing 10 , At the in 3 The selected view is the direction of rotation Y of the impeller 16 thus counterclockwise from the beginning of the delivery channel 20 until the end of the delivery channel 20 or to the outlet 30 and then over the interruption area 36 back to the beginning of the conveyor channel 20 that's the inlet 18 opposite.

By circumferential corresponding webs 41 and grooves 43 on the housing parts 10 . 12 and on the disk-shaped central part 34 of the impeller 16 becomes a seal from the delivery channels 20 . 22 towards the interior of the wheel 16 generated.

The impeller blades 32 of the impeller 16 have a radially outer end region 44 and one between the disk-shaped middle part 34 and the radially outer end portion 44 arranged radially adjacent intermediate region 46 on. In this intermediate area 46 are the impeller blades 32 by a radially extending partition 48 in a first row axially opposite to the first conveying channel 20 and a second row axially opposite to the second conveyor channel 22 divided, so that two vortex channels are formed, each through one of the delivery channels 20 . 22 with the facing part of the impeller blades 32 be formed. There is no separation in the radially outer end region, so that in this area an exchange of the medium between the delivery channels 20 . 22 is possible.

The outer diameter of the delivery channels 20 . 22 is slightly larger than the outer diameter of the impeller 16 , which is for example about 85 mm, so that a fluidic connection between the two delivery channels 20 . 22 also outside the outer circumference of the impeller 16 consists. It is thus a radial gap 50 between the radially delimiting housing wall 42 and the radial end of the impeller in the order of 3 to 6 mm, with a correspondingly larger impeller 16 also this gap 50 is correspondingly larger to choose. Between the impeller blades 32 thus become radially outwardly open pockets 52 formed, in which the medium is accelerated, so that its pressure over the length of the delivery channels 20 . 22 is increased.

The size of this gap 50 arises in particular against the background of the inventive design of the impeller blades 32 , In the illustrated embodiment, this is the impeller blades 32 in the intermediate area 46 by an angle of about 10 ° against the direction of the impeller 16 employed in comparison to the radial direction Z. In the adjoining end area 44 they are in turn compared to the intermediate area 46 inclined by an angle of 20 ° in the direction of rotation or extend in this end 44 set at an angle of 10 ° in the direction of rotation to the radial direction Z. This results in an additional acceleration of the medium during the rotation of the impeller 16 at a speed of about 12,000 to 24,000 rpm.

In addition, the impeller blades 32 also in cross section so in a section perpendicular to Circumferential or rotational direction Y over its entire substantially radial extent V-shaped, so that each leg of each impeller blade 32 its opposite conveyor channel 20 . 22 is assigned and in the intermediate area the partition 48 is arranged between the legs. In comparison to a vector running parallel to the axis of rotation X, each leg is about 15 ° in the direction of rotation of the impeller 16 inclined and towards the opposite conveyor channel 20 . 22 formed extending. In other words, the axial ends of the two legs are each formed in advance compared to the point at which the legs are brought together.

Upon rotation of the impeller 16 via the drive unit 14 the gas comes out of the delivery channels 20 . 22 in the radially inner intermediate region 46 in the pockets 52 one. By the rotation and the shape of the blades 32 creates a maximum stagnation of the gas in the central region of each blade 32 , This collected gas is then accelerated outward over the axially middle region, with the slope of the end region 44 generates an additional acceleration above the normal rotational speed. With this pressure, the gas in the direction of the radially bounding housing wall 42 accelerated, which is correspondingly arranged at a greater distance, so that a larger space for deflection in the direction of the delivery channels is available. These are then again flowed through from radially outside to inside. Then the gas enters the pockets again 52 to be accelerated again. This results in a helical movement along each conveyor channel from the inlet 18 to the outlet 30 , This has a round cross-section, whereby the available for exiting cross-section of a bag gradually decreases upon rotation. This leads to low noise and only a small gas flow over the interruption area, which in turn improves the efficiency of the blower.

It is thus created a side channel blower for compressible media, which generates high differential pressures and flow rates, without an increased energy requirement, so that the efficiency compared to known blowers is improved. In addition, a variety of different operating points can be approached with a blower alone by changing the speed without bad efficiencies.

However, it should be clear that various modifications of the side channel blower described in the embodiment are possible without departing from the scope of the main claim. Thus, the drive, the inlet and outlet, the interruption and outlet contours or the attachment and sealing structures can be modified. Other changes are also conceivable.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 6422808 B1 [0006]
• US 5299908 B1 [0007]

Claims (7)

Side channel blower for an internal combustion engine with a flow housing, an impeller ( 16 ), which is rotatably disposed in the flow housing, impeller blades ( 32 ), which at the radially outer region of the impeller ( 16 ) are formed and are designed to be open radially outward, a radial gap ( 50 ) between the impeller ( 16 ) and one the impeller ( 16 ) radially surrounding housing wall ( 42 ), an inlet ( 18 ) and an outlet ( 30 ) as well as two the inlet ( 18 ) with the outlet ( 30 ) connecting funding channels ( 20 . 22 ) for a gas axially opposite the impeller blades ( 32 ) in the flow housing ( 10 . 12 ) and via spaces between the impeller blades ( 32 ) are fluidly connected to each other, a drive unit ( 14 ) over which the impeller ( 16 ) is drivable, an interruption area ( 36 . 38 ) between the outlet ( 30 ) and the inlet ( 18 ), in which the funding channels ( 20 . 22 ) are interrupted in the circumferential direction, characterized in that the impeller blades ( 32 ) are formed in cross-section V-shaped such that the impeller blades ( 32 ) in the direction of rotation inclined to the axis of rotation in the direction of its opposite conveying channel ( 20 . 22 ). Side channel blower for an internal combustion engine according to claim 1, characterized in that the blades ( 32 ) to the axis of rotation by 5 ° to 20 ° in the direction of rotation of the impeller ( 16 ) are inclined. Side channel blower for an internal combustion engine according to one of claims 1 or 2, characterized in that the impeller vanes ( 32 ) in its radially outer end region ( 44 ) in the direction of rotation of the impeller ( 16 ) to the radially inner adjacent intermediate region ( 46 ) of the impeller blades ( 32 ) are inclined. Side channel blower for an internal combustion engine according to claim 3, characterized in that the radial end region ( 44 ) of the impeller blades ( 32 ) is formed inclined to the radial direction 5 ° to 20 ° in the direction of rotation and the adjoining intermediate region ( 46 ) of the impeller blades ( 32 ) is formed at 5 ° to 20 ° counter to the direction of rotation inclined to the radial direction. Side channel blower for an internal combustion engine according to one of the preceding claims, characterized in that the radial gap ( 50 ) between the end portion of the impeller blades ( 32 ) and the radial impeller ( 16 ) surrounding housing wall ( 42 ) in the area of the production channels ( 20 . 22 ) is 0.03 to 0.1 times the impeller diameter. Side channel blower for an internal combustion engine according to one of the preceding claims, characterized in that the outlet ( 30 ) in the flow housing ( 10 . 12 ) tangentially from the delivery channels ( 20 . 22 ) and has a circular cross section, which is substantially the cross section of the conveying channels ( 20 . 22 ) corresponds. Side channel blower for an internal combustion engine according to one of the preceding claims, characterized in that (at the level of the connection between the two legs of the V-shaped impeller blades 32 ) is formed a partition which extends radially over the intermediate region ( 46 ) of the impeller blades ( 32 ) extending to the end region ( 44 ) adjoins.

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